Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Germany.
Center for Radiology and Nuclear Medicine, DIAKOVERE gmbh, Germany.
Eur J Radiol. 2020 Apr;125:108900. doi: 10.1016/j.ejrad.2020.108900. Epub 2020 Feb 13.
To determine the clinical impact of CT dose management team on radiation exposure and image quality.
2026 clinical routine CT examinations of 1315 patients were evaluated retrospectively. A CT dose management team was established as an integral part of the radiological department. It identified 5 CT protocols (A-E), where national reference values were exceeded the most. Those reference values included specifically the mean volumetric CT dose index (CTDI) and the mean dose-length product (DLP). Baseline data (period 1) and follow up data (period 2) were obtained after reduction of tube voltage and increase of pitch or noise index. Signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were calculated to compare image quality. Two-sided t-tests were performed.
Mean CTDI and mean DLP of the chest protocol (A) decreased after reduction of tube voltage (P < 0.01). In the chest/abdomen/pelvis protocol (B), the increase of noise index resulted in a significant mean CTDI decrease (P < 0.02) without statistical significance of mean DLP (P < 0.12). In the abdomen/pelvis protocol (C), mean CTDI (P = 0.01) and mean DLP (P < 0.01) were significantly lower after noise index increase. In the staging of hepatocellular carcinoma (D), mean CTDI and mean DLP were significantly lower after increase of pitch and noise index (P < 0.01). The lung protocol (E) yielded no significant changes after modulation (P > 0.05). SNR (protocol A) was significantly higher in period 2 (P < 0.04). Protocol D showed significantly lower selected SNR and CNR (P < 0.02).
Establishing an operating dose management team as a standard for good clinical practice helps to considerably reduce CT radiation dose while preserving image quality.
确定 CT 剂量管理团队对辐射暴露和图像质量的临床影响。
回顾性评估了 1315 名患者的 2026 例临床常规 CT 检查。将 CT 剂量管理团队作为放射科的一个组成部分建立。它确定了 5 个 CT 协议（A-E），其中国家参考值超标最严重。这些参考值具体包括平均容积 CT 剂量指数（CTDI）和平均剂量长度乘积（DLP）。在降低管电压和增加螺距或噪声指数后，获得基线数据（第 1 期）和随访数据（第 2 期）。计算信噪比（SNR）和对比噪声比（CNR）以比较图像质量。进行了双侧 t 检验。
胸部协议（A）的平均 CTDI 和平均 DLP 在降低管电压后降低（P < 0.01）。在胸部/腹部/骨盆协议（B）中，噪声指数的增加导致平均 CTDI 显著降低（P < 0.02），但平均 DLP 无统计学意义（P < 0.12）。在腹部/骨盆协议（C）中，噪声指数增加后平均 CTDI（P = 0.01）和平均 DLP（P < 0.01）显著降低。在肝细胞癌分期（D）中，增加螺距和噪声指数后平均 CTDI 和平均 DLP 显著降低（P < 0.01）。在肺协议（E）中，调制后无显著变化（P > 0.05）。第 2 期（P < 0.04）的 SNR（协议 A）显著升高。协议 D 显示出显著降低的选定 SNR 和 CNR（P < 0.02）。
建立运营剂量管理团队作为良好临床实践的标准有助于在保持图像质量的同时显著降低 CT 辐射剂量。
